Hmm....

I wanna swap a obd2 engine into my obd1 civic is there a obd1 to obd2 harness available for the ecus?

 

http://hondaswap.com/adverts/adclick.php?b...ww.boomslang.us

yep
or try hasport, or some of the other ads on this site.

 

Whats the difference between obd2a and obd2b?

 

OBD 2a: 96-98
OBD 2b: 99-

The OBD 2b ecu will not hook up to a 96-98 harness... I tried...

 

What motor going into what car?
I got away without needing a conversion harness
for an obd2 b16 going into my obd1 civic using the obd2a GSR Harness.

 

OBD2 GSr or type r in to a OBD1 Civic DX

 

I'm not more than 94% positive, but since the obd2 GSR harness breaks off at shock towers like the civic harness,it would be plug n play, except you will need an obd1 Ecu.
..
[edit]
After re-reading your first post, i guess you weren't asking about the engine harness anyways.
If you go Type R, and want to use the Type R ecu, you will need to use an obd1 to obd2 conversion harness.
If you go GSR, just get an obd1 GSR ecu.
Sorry I'm sleeping

 

i have an 01 JDM ITR engine in my 93 sol running off an OBD-1 ECU
no OBD conversion harnesses required

 

What ecu are you using, out of curiosity?

 

im running it off a chipped P28 "tuned" with a VAFC

 

^-- wants to crome up the itr but E won't let me :cry2:

 

aww ya poor thing.
Fly to Az, and you can tune my friend's R for free!